Disorder Potentials near Lithographically Fabricated Atom Chips

TL;DR

This paper demonstrates that high-quality lithographically fabricated gold layers significantly reduce disorder potentials in atom chips, with residual magnetic field variations linked to local wire properties, as shown through Bose-Einstein condensate measurements.

Contribution

It provides experimental evidence that improved fabrication reduces magnetic disorder potentials, enhancing atom chip performance for quantum applications.

Findings

Disorder potentials are reduced by about two orders of magnitude.

Residual magnetic field variations are due to local wire properties.

Surface distance measurements down to a few microns reveal detailed current flow variations.

Abstract

We show that previously observed large disorder potentials in magnetic microtraps for neutral atoms are reduced by about two orders of magnitude when using atom chips with lithographically fabricated high quality gold layers. Using one dimensional Bose-Einstein condensates, we probe the remaining magnetic field variations at surface distances down to a few microns. Measurements on a 100 um wide wire imply that residual variations of the current flow result from local properties of the wire.